Hello, If what you say is certainly the hoemeopathic medication is for pollen immunotherapy, then there would not be any side effects if he takes the usual medications. However, as most of the homeopathic medications have sugar coating of some sort, blood glucose levels may get higher but unlikely given that he has taken only one dose. The homeopathic medications usually come in little bottles, so unsure how he managed to do this. If they were in the form of tablets, I would suggest keeping your medications separately from his, such as in a different drawer or cabinet to prevent this happening again. Best Wishes.